Virtual shopping malls operated on the Internet have become prevalent. The users can access shopping mall sites using a personal computer or cell-phone and browse various products and services exhibited within the shopping malls. Then, if there is a product or service the user likes, the user can add the product or service to his purchase list generally called a cart or shopping basket and then purchase it.
Online shopping malls have been modified in many ways in order to attract more customers and increase the sales at virtual stores. For example, Patent Literature 1 describes an online shopping mall of which the virtual stores provide the links to each other so as to mutually increase users.
Furthermore, generally, not only open information the user wishes to view but also notice information the store operator wants the user to view are shown so that information is conveyed to the user properly.